The invention relates to a process of extracting the hot strand from a continuous casting mould, wherein a starter bar head in the form of tongs is inserted; into the lower opening of the mould, thereby closing the lower opening, and is connected to a starter bar or an articulated starter bar (chain) as well as to an apparatus for carrying out this process.
Starter bar heads, in particular starter bar heads for wide slabs, which are connected to rails transverse to the longitudinal axis of the strand and are introduced into the lower opening of the mould in order to form a force-locking connection with the hot strand, have been known. This kind of connection has, however, the disadvantage that the preparation of the starter bar head by cutting the rails as well as packing and sealing the rails requires a lot of time and material.
Furthermore hook-shaped starter bar heads have been known which are introduced into the lower opening of the mould and fill the cross-section of the mould. When the molten metal poured into the mould has solidified, a counter hook forms which serves as a force-locking connection with the hook-shaped starter bar head. After the extraction, the starter bar head must, however, be separated from the hot strand by a turning or tilting movement, a separate actuating means being necessary therefor. This constitutes an additional constructional burden and -- depending on the overall construction of the plant -- cannot easily be accommodated.
Finally a tong-shaped starter bar head, whose nippers in their closed position embrace a rail piece, has become known. After the introduction of the tong-head into the mould opening, the rail is cast around it and thus a force-locking connection is produced. The nippers of the tongs are retained closed and in their open positions by a locking mechanism consisting of arresting cams and a rotating wedge, so that manual opening and closing manipulations are necessary.